In order to reduce the difference of the vibration response between the finite element simulation model and the actual physical model, the parameter modification method for the finite element simulation model of rolling bearings is proposed. Firstly, the finite element simulation models of normal bearings with different clearances are created, and their vibration responses are obtained. Secondly, a joint credibility analysis method based on kurtosis and margin factors is proposed, and the optimal bearing clearance is obtained. Finally, a bearing fault simulation model is established based on optimizing the bearing clearance. The results show that the matching degree between the simulated vibration response and the actual vibration response has been improved.